Bicycle frame



FIG. 1 is a right side elevation of a bicycle frame showing my new design.

FIG. 2 is a perspective view.

FIG. 3 is a front elevation view thereof.

FIG. 4 is a rear elevation view thereof.

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a bicycle frame, as shown and described. 